1. Field of the Invention
The present invention relates to metal shelving assemblies; more particularly, to stand-alone metal shelving assemblies; and most particularly, to a modular stand-alone metal shelving system that is easily assembled without tools.
2. Discussion of the Related Art
Stand-alone metal shelving assemblies are well known. By stand-alone is meant a shelving assembly that does not require a wall for a portion of its support or stability. A stand-alone assembly may be free-standing away from a building wall or other support or stabilizing element.
A prior art modular shelving system is disclosed in U.S. Pat. No. 4,558,647. A modular shelving unit comprises at least two upright members and at least two shelf elements which engage oppositely spaced-apart upright members to form a shelving structure. The upright members are made of a latticework of welded wire which is secured at two opposite edges in support beams (corner posts). The shelf elements are also made of a latticework fixed along two opposite edges thereof in support beams. The support beams of the shelf elements have means at each end for engaging the latticework of an upright member. The latticework of the shelf elements is relatively flexible and may require additional structure and rigidity by means of auxiliary support beams positioned under the shelves for this purpose. The formed structure has relatively little strength against rhombic collapse in the X (sideways) direction. Thus, one or more diagonal turnbuckle assemblies are recommended across the rear of the unit to provide added structural integrity to the shelving to prevent rhombic collapse.
A shortcoming of such a prior art modular shelving system is the fabrication expense of the shelves, which require, first, formation of a welded latticework of wires; second, formation of channel beams for the shelf edges; third, formation of hooks on the ends of the channel beams; fourth, crimping of the ends of the wires for insertion into the beam channels; and fifth, crimping of the beam channels to retain the ends of the wires. Thus, formation of each shelf is a multiple-step, multiple-process operation requiring welding, cutting, stamping, forming, and assembling of multiple components.
A further shortcoming is that the resulting shelf is relatively weak against folding in the Y (front-to-back) direction and requires one or more supplementary beams for heavy loads.
A still further shortcoming is that the shelves are open latticework and therefore are useless for storing small items which cannot stand on the latticework and may even fall through, requiring therefore a supplementary continuous shelf liner.
A still further shortcoming is the lack of inherent rhombic stability, requiring addition of one or more diagonal turnbuckles to prevent rhombic collapse under load.
What is needed in the shelving art is an improved modular metal shelving system wherein an entire stand-alone shelving assembly is easily assembled without need for any tools; wherein each individual shelf may be readily repositioned at a different height; wherein the shelves may be formed inexpensively; wherein the shelves are continuous and thus can fully support objects of any size; wherein the assembly is inherently strong against rhombic collapse in both the X and Z directions; wherein the assembly may be assembled or disassembled rapidly and easily; and wherein the assembly is readily modular.
It is a primary objective of the invention to provide a shelving assembly which is easily assembled without need for any tools, wherein each individual shelf may be readily repositioned at a different height, wherein the shelves may be formed inexpensively, wherein the shelves are continuous and thus can fully support objects of any size, wherein the assembly is inherently strong against rhombic collapse in the X and Z directions, wherein the assembly may be assembled or disassembled rapidly and easily, and wherein the assembly may be readily combined modularly with additional assemblies.